notify-send dumps core if notification message is invalid UTF-8
$ notify-send -- $'\U001FF642'
(notify-send:9256): GLib-CRITICAL **: 23:56:12.099: g_variant_new_string: assertion 'g_utf8_validate (string, -1, NULL)' failed
Trace/breakpoint trap (core dumped)
$
The command-line tool doesn’t check that the inputs are valid UTF-8. If they are not, an assertion fails in g_variant_new_string()
.